COLUMBIA, S.C. (AP) — Two lawsuits filed Tuesday allege that South Carolina corrections officials violated prisoners’ constitutional rights by failing to prevent a riot in which seven inmates were killed last year.

In the lawsuits, advance copies of which were provided to The Associated Press before they were filed, representatives for the estates of two male inmates killed in the April 2018 insurrection at Lee Correctional Institution say security officers and agency personnel knew about dangerous problems at the prison but did nothing to fix them, violating the men’s due process rights and subjecting them to cruel and unusual punishment.

The suits, filed by the estates of Raymond Angelo Scott and Corey Scott, who were not related, blame Corrections Department officials for numerous problems, including broken cell door locks, chronic overcrowding and understaffing they say made it easier for inmates bent on violence to get away with having homemade knives, hatchets and other contraband weapons.

With only one officer monitoring more than a hundred inmates in the dorm — a regular occurrence due to staffing shortages, officials have said — Lee inmates were “largely left unsupervised throughout the day and night,” leading to a dangerous situation, according to the lawsuits.

No charges have been filed in the riot, which raged for more than seven hours in Bishopville, about 40 miles (65 kilometers) east of Columbia. State police spent a year reviewing the case before forwarding findings to prosecutors, who are still reviewing them. The state Corrections Department didn’t immediately comment on the lawsuits.

Officials have said the violence — the worst U.S. prison riot in 25 years — began as a battle over contraband and territory. Corrections officials have blamed it in part on illegal cellphones. Corrections Director Bryan Stirling has said they represent the greatest security threat inside prisons because they give inmates an unmonitored way to communicate with the outside world and each other, and in some cases to wage criminal acts from behind bars.

Most of the slain were stabbed or slashed; others appeared to have been beaten. One inmate described bodies “literally stacked on top of each other, like some macabre woodpile.”

The lawsuits detail a chronology of the violence, which began about 7:15 p.m. on April 15, 2018. When inmates began fighting in one dorm, according to the lawsuits, the one officer on duty did nothing to stop it, ultimately getting out safely, abandoning and locking the unit, leaving inmates “alone and unsupervised.”

Two hours later, as the rioting spread to another dorm, an officer finally called for first responders after seeing “numerous hatchets and knives” in inmates’ hands, the suits say. Yet even after Raymond Scott and Corey Scott were attacked, officers locked inmates in the yard and didn’t try to render aid, they say.

Corrections SWAT units tried to gain control about 1 a.m. on April 16, and the prison was secured about two hours later. By that time, according to the lawsuits, both men had died.

“I don’t see how it could have been more dangerous for the inmates who were in there,” Carter Elliott, lead attorney on the case, told the AP. “It was coming like a freight train.”

For several months leading up to the insurrection, the AP communicated with a Lee prisoner who used a contraband cellphone to offer insight into life behind bars. Describing frequent gang fights with homemade weapons, he said prisoners roamed freely, had easy access to cellphones and drugs, and were often left to police themselves.

“ALL of the doors to the cells are broken,” wrote the inmate, who spoke to the AP on the condition of anonymity because his cellphone was illegal and he feared retribution from other prisoners. “At any time, I can let myself out of my cell.”

Video obtained from the same inmate backed up claims about plentiful homemade weapons and broken locks.

In the year since the riot, numerous improvements have been implemented at institutions, including Lee, officials have said. This spring, officials invited reporters to tour Lee, where they demonstrated a $1 million cell door locking system to prevent future intrusions.

New measures also include perimeter netting, scanning devices and drone monitoring to shut cellphones down. Officials still aren’t able to fully use cell signal-jamming technology Stirling wants, however.

Corey Scott, 38, had been serving a 22-year sentence for crimes including assault and battery and kidnapping. Raymond Angelo Scott, 28, had been sentenced to 25 years on charges related to a robbery in which he allegedly shot a store clerk.

Casualties of the riot were all convicts, but their crimes didn’t justify such violence, said state Rep. Justin Bamberg, an attorney working on the cases.

“Sometimes people break the law. But it’s not always a death sentence. How can government be OK with that?”